The Syncardia™ total artificial heart: in vivo, in vitro, and computational modeling studies

Abstract

The SynCardia™ total artificial heart (TAH) is the only FDA-approved TAH in the world. The SynCardia™ TAH is a pneumatically driven, pulsatile system capable of flows of >9 L/min. The TAH is indicated for use as a bridge to transplantation (BTT) in patients at imminent risk of death from non-reversible bi-ventricular failure. In the Pivotal US approval trial the TAH achieved a BTT rate of >79%. Recently a multi-center, post-market approval study similarly demonstrated a comparable BTT rate. A major milestone was recently achieved for the TAH, with over 1100 TAHs having been implanted to date, with the bulk of implantation occurring at an ever increasing rate in the past few years. The TAH is most commonly utilized to save the lives of patients dying from end-stage bi-ventricular heart failure associated with ischemic or non-ischemic dilated cardiomyopathy. Beyond progressive chronic heart failure, the TAH has demonstrated great efficacy in supporting patients with acute irreversible heart failure associated with massive acute myocardial infarction. In recent years several diverse clinical scenarios have also proven to be well served by the TAH including severe heart failure associated with advanced congenital heart disease. failed or burned-out transplants, infiltrative and restrictive cardiomyopathies and failed ventricular assist devices. Looking to the future a major unmet need remains in providing total heart support for children and small adults. As such, the present TAH design must be scaled to fit the smaller patient, while providing equivalent, if not superior flow characteristics, shear profiles and overall device thrombogenicity. To aid in the development of a new “pediatric,” TAH an engineering methodology known as “Device Thrombogenicity Emulation (DTE)”, that we have recently developed and described, is being employed. Recently, to further our engineering understanding of the TAH, as steps towards next generation designs we have: (1) assessed of the degree of platelet reactivity induced by the present clinical 70 cc TAH using a closed loop platelet activity state assay, (2) modeled the motion of the TAH pulsatile mobile diaphragm, and (3) performed fluid-structure interactions and assessment of the flow behavior through inflow and outflow regions of the TAH fitted with modern bi-leaflet heart valves. Developing a range of TAH devices will afford biventricular replacement therapy to a wide range of patients, for both short and long-term therapy.

Design of a Pulsatile Flow Facility to Evaluate Thrombogenic Potential of Implantable Cardiac Devices

“…Thrombus formation in cardiovascular hardware is a complex, multistep process starting with platelet activation and culminating in formation of solid clot [2,9,11,15,42,50). Magnitude and dura tion of pathophysiological shear stress exposure have been found to be two dominating factors in thrombus formation, with cell lysis and tissue factors aiding the process [58].…”

“…This affects the performance of a broad range of cardiovascular devices such as prosthetic valves, stents, bypass pumps, and flow-assist devices [6][7][8][9][10][11][12][13][14][15][16][17][18][19], All these hardware are designed to mimic the function of the heart either totally or partially. Ventricular assist devices are increasingly being used in congestive heart failure patients and have been proven to be more effective than treatment through drug therapy alone [6][7][8][9][10][11]20]. PHVs are widely used as a replace ment for diseased heart valves.…”

Novel Optical Position Sensing for Miniaturized Applications and Validation in a Total Artificial Heart

“…So far, only one temporary TAH, the Syncardia TAH (SynCardia Systems Inc., Tucson, USA), received FDA and CE approval [2]. However, its extra-corporal worn pneumatic drive *B.…”

Artificial heart creation: what problems are to be solved?

“…But unfortunately the recognized American and French artificial heart developers do not take this novel concept into account [7][8][9][10][11][12]. As a rule they use only 5 cardiac cycle phases which are incompletely and inconsistently described and interpreted in the classical research.…”